Organic derivatives of tetravalent tin and compositions containing the same



Patented June 1, 1954 UNITED STATES PATENT OFFICE ORGANIC DERIVATIVES OF TETRAVALENT TIN AND COMPOSITIONS THE SAME CONTAINING William E. Leistner, Brooklyn, and Arthur 0. Becker, Richmond Hill, N. Y., assignors to Argus Chemical Laboratory, Inc., a corporation of New York No Drawing. Application May 20, 1952, Serial No. 289,011

wherein R stands for a radical selected from the group consisting of .alkyl, aryl, oxyalkyl and oxyaryl, and the furfuryl and tetrahydrofurf-uryl radicals, X for the anion of a mercapto fatty acid having from to 20 carbon atoms, and n for an integral number from 1 to 3.

Examples for R are alkyls, such as methyl, ethyl, butyl, octyl, dodecyl, and octadecyl; aryls, such as phenyl, tolyl, or xylyl; oxyalkyl and oxyaryl, such as Cal-I70, CAI-I90, CsHrzO, Cal-I50, CsI-I4(CH3)O; CeHs(CH3)2O; and the furfuryl and tetrahydrofurfuryl groups.

Examples for X are anions of mercapto fatty acids, such as dodecyl mercapto isobutyric acid, octyl mercapto propionic acid, benzyl mercapto isobutyric acid, and phenyl mercapto acetic acid. Taking as specific examples the dodecyl mercapto propionic acid and butyl tin compounds, the products may have the following formulas:

The novel tin compounds according to our inj vention are oily liquids of high viscosity or solids gmelting at low temperatures, Whose composition has in each case been ascertained by analysis.

They are soluble in many organic solvents, for instance in ether, benzene, toluene, chloroform, carbontetrachloride, etc.

A general method to prepare these compounds is first to prepare the desired mercapto fatty acid and subsequently to react the acid with an organic tin oxide, or a stannonic acid containing 5 Claims. fwi. 260-45115) an organic radical, or to react the alkali metal salt of the acid with an organic tin halide.

The invention will now be illustrated by a number of examples, but it should be understood that these are given by way of illustration and not of limitation and that many variations in the compounds given and the amounts indicated can be made without departing from the spirit of the invention and the scope of the appended claims.

Example 1 The preparation of dibutyl-tin di-dodecyl mercapto isobutyrate (3H3 (C4H9)iS]1-(O O C. CH. CH2. S C 2H25)z To 800 g. n-dodecyl mercaptan are added 2 g. sodium-methylate. To this mixture 400 g. methylmethacrylate are added slowly While stirring. An exothermic reaction occurs and the temperature rises spontaneously to about C. By the further addition of the methylmethacrylate, the reaction mixture is maintained at this temperature. Gradually, the viscosity of the solution increases. When the whole amount of methylmethacrylate has been added, one more gram of sodium methylate is added without causing a rise in temperature. Thereafter, the solution is heated on a boiling water bath for /2 hour.

After cooling down, a solution of 160 g. NaOH in 700 cc. water is slowly added with stirring, which causes a slight rise in temperature. After addition of the whole amount of NaOI-I, the mixture is heated to 100 C. for one hour, in order to complete hydrolysis. On cooling, the reaction mixture solidifies to a soaplike mass. This is acidified with HCl, whereby the mercapto acid separates as an oil. V

g. dry acid 25 g. dibutyl-tin oxide, and

50 cc. benzene, to which 0.1 g. paratoluene sulfonic acid was added,

are refluxed for about 1 hour, whereby 1.7 cc. water are removed by azeotropic distillation.

The reaction mixture is filtered in order to remove slight impurities, and benzene is distilled off. In the filtrate, there remains an oily residue.

which solidifies in the ice box and melts again at room temperature.

Analysis Sn S calc l4. 5 7. 9 found 14. 1 8.

Example 2 Preparation of tributyl-tin octyl mercapto propionate (021%) 3511(OOCCH2CH2SC8H1T) Octyl mercapto propionic acid is prepared in precisely the same way as in Example 1 from:

292 g. ethylhexyl mercaptan, and

175 g. methyl acrylate in the presence of 2 g. sodium methylate as catalyst.

22 g. of the dry acid were neutralized with 4 g. NaOI-I, and

32.5 g. tri butyl--tin chloride and 50 cc. benzene were added.

The resulting mixture was refluxed for 1 hour,

and the sodium chloride formed was filtered oil. The residue of the filtrate after distilling oil the solvent is very similar to the product of Example 1.

Analysis Sn S Cale 23. 3 G. 3 Found 22. 8 6. 2

Example 3 Preparation of isopropyl-tin tribenzylmercapto isobutyrate CHi C3H7SH(O o 0611.01.12. s CHZC Hs):

In the same way as in Examples 1 and 2 benzyl mercapto-isobutyric acid was prepared from were refluxed for 1 hour and 8.5 cc. water removed by azeotropic distillation. Slight impurities are filtered off and benzene is removed by distillation.

The residue is in appearance and properties similar to the material obtained according to Example 1. Analysis:

Cale. values 15. 0 12. 2 Found values 15.1 12. l

The novel compounds made according to the method described above may be used for various purposes. They are excellent stabilizers for chlorinated resins or other high molecular weight halogenated material, and may be used as antioxidants. They may also be interesting as such, or as intermediates for pharmaceuticals and cosmetics. As to their use for stabilizing chlorine-containing organic compositions, we wish to emphasize the superiority of these products above compounds of similar structure, such as dibutyl tin dilaurate. The presence of the sulfur in the molecule increases the compatibility with the product to be stabilized. Furthermore, the sulfur present acts as an antioxidant which improves the stabilizing efiect.

The amount of the compounds to be used as stabilizers is from 0.1 to 10% by weight of the resinous composition.

In the following, examples will be given for the manufacture of plastic compositions in which the compound according to the present invention is used as a stabilizer.

Example 4 100 parts of vinylite VYNW (vinyl chloride and acetate copolymer), 50 parts of dicotylphthalate, and 2 parts of the product of Example I as stabilizer are mixed by tumbling for a period of one hour. The whole mass is then transferred to a Banbury mixer and fused for 10 min. at a temperature of approximately 300 F. It is then dropped and transferred to a warmup mill, whose roll temperature is likewise maintained at 300 F. The material is then fed as needed to a 3 or 4 roll calender. The roll temperatures of the calender range from 280350 F. The vinyl compound is calendered into a film at .004 inch or any other desirable gage.

Example 5' A comparison test was made in which chlo rinated parafiin was heated over a period of time, without any addition on the one hand, and with addition of a stabilizer made according to the invention on the other hand.

In this test, a nitrogen current was passed through chlorinated paraffin containing 4.0% chlorine, at a temperature of 150 F. for 12 hours. During the test, the paraffin lost chlorine.

The same chlorinated paraffin, to which 3% of the product obtained in Example 3 were added, was treated in a similar manner and showed a loss of only 1.1% chlorine after 12 hours.

Example 6 The following procedure is used to advantage in making a finished solution of the resin. We use 100 parts of vinylite VYNW (vinyl chloride and acetate copolymer) along with parts of tricresylphosphate. ihis is weighed into a dry blender; 1 part of stabilizer (made as described in Example 2) is then added. The whole mass is agitated by tumbling for 30 minutes and then transferred to a 2-roll mill whose roll temperatures are about 240 F. The mass is fluidized on the mill and then sheeted into strips which are added to a mixture consisting of 3 parts of methyl ethyl ketone and 1 part of toluene in a conventional mixer. The compound is agitated at room temperature in the mixer until complete solution results. The proportion of solvent used will vary with the concentration of solution desired, as, for instance, from 500 to 3,000 parts of solvent to parts of the vinyl chloride resin used.

What we claim is:

1. As a new compound, a product corresponding to the formula wherein R stands for a radical selected from the group consisting of alkyl, aryl, oxyalkyl and oxyaryl, and the furfuryl and tetrahydrofurfuryl radicals, X for the anion of a mercapto fatty acid selected from the group consisting of alkyl and aryl mercapto fatty acids having from 5 to 20 carbon atoms, and n for an integral number from 1 to 3.

2. As a new compound, dibutyl tin di-dodecylmercapto-isobutyrate.

3. As a new compound, tributyl tin octylmercaptopropionate.

4. As a new compound, isopropyl tin tribenzylmercapto-isobutyrate.

5. A stabilized chlorine-containing resinous composition containing 0.1% to 10% by weight of the compound of claim 1.

References Cited in the fiie Of this patent UNITED STATES PATENTS Number Name Date 2,479,918 Fincke et a1 Aug. 23, 1949 2,489,518 Burt Nov. 29, 1949 2,591,675 Church et a1 Apr. 8, 1952 2,592,926 Mack et a1 Apr. 15, 1952 

1. AS A NEW COMPOUND, A PRODUCT CORRESPONDING TO THE FORMULA 